<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>
    const demo = ()=>{
        var a= 10;
        console.log(this)
    }

    function demo2(){
        console.log(this)
    }

    demo();

    demo2()
</script>

</body>
</html>